The 4000 SERIES is a family of integrated circuits (ICs) first
introduced in 1968. Almost all IC manufacturers active during this
initial era fabricated models for this series. It is still in use
today.

The
4000 series4000 series was introduced as the CD4000 COS/MOS series in 1968
by
RCARCA as a lower power and more versatile alternative to the 7400
series of transistor-transistor logic (TTL) chips. The logic functions
were implemented with the newly introduced Complementary
Metal–Oxide–Semiconductor (CMOS) technology. While initially
marketed with "COS/MOS" labeling by
RCARCA (which stood for Complementary
Symmetry Metal-Oxide Semiconductor), the shorter
CMOSCMOS terminology
emerged as the industry preference to refer to the technology. The
first chips in the series were designed by a group led by Albert
Medwin .

Wide adoption was initially hindered by the comparatively slower
speeds of the designs compared to TTL based designs. Speed limitations
were eventually overcome with newer fabrication methods, leaving the
older TTL chips to be phased out. The series was extended in the late
1970s and 1980s with new models that were given 45xx and 45xxx
designations, but are usually still regarded by engineers as part of
the 4000 series. In the 1990s, some manufacturers (e.g. Texas
Instruments ) ported the
4000 series4000 series to newer H
CMOSCMOS based designs to
provide greater speeds.

DESIGN CONSIDERATIONS

The CD4007 on a breadboard

The
4000 series4000 series facilitates simpler circuit design through relatively
low power consumption, a wide range of supply voltages , and vastly
increased load-driving capability (fanout) . This makes the series
ideal for use in prototyping LSI designs. While TTL based design is
similarly modular , it requires meticulous planning of a circuit's
electrical load characteristics. Buffered models can accommodate
higher electrical currents, but have a greater risk of introducing
unwanted feedback . Many models contain a high level of integration,
including fully integrated 7-segment display counters , walking ring
counters , and full adders .